Bump actions/download-artifact from 5 to 6

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5...v6)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/build_wheels.yml

@@ -60,7 +60,7 @@ jobs:
     # if: github.event_name == 'release' && github.event.action == 'published'
     if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
     steps:
-    - uses: actions/download-artifact@v5
+    - uses: actions/download-artifact@v6
       with:
         pattern: cibw-*
         path: dist